Photogenics is the top-of-the-line graphics app for the PPC. I don't know how fast it is on the old Jornadas though. I am a beta tester, and it was more than fast enough on my Casio e-125
There are two versions. Personal edition only has ONE layer, with a few less tools and is priced at $29. Basically it is for the beginner.
I have the $49 package, with multiple layers and additional tools. If you are adept at computer graphics you should get this one, as the cheaper Personal Edition won't be powerful enough for you.